| Number | Name | Date | Kind |
|---|---|---|---|
| 2828321 | Bullock | Mar 1958 | |
| 3061619 | Braunwarth et al. | Oct 1962 |
| Number | Date | Country |
|---|---|---|
| 2554703 | Jun 1977 | DEX |
| Entry |
|---|
| Chemical Abstracts, vol. 72, 1970, abstract No. 90181y, Trofimov _et al. |
| Chemical Abstracts, vol. 87, 1977, abstract No. 152195b, Moeller et al. |